The present disclosure relates to an image forming apparatus including a housing which supports a cleaning blade and is attachable to and detachable from an apparatus main body.
Conventionally, in an image forming apparatus, a toner image is formed on a photosensitive drum by a developing device, and the toner image is transferred onto a sheet at a transfer portion. The image forming apparatus further includes a fixing portion. The sheet on which the toner image has been transferred is subjected to a fixing process at the fixing portion and then discharged. Untransferred toner remains on the photosensitive drum from which the toner image has been transferred. Thus, a technique is known in which a cleaning blade contacts with the surface of the photosensitive drum. The cleaning blade removes the untransferred toner from the surface of the photosensitive drum.
The cleaning blade is disposed in a housing which is attachable to and detachable from an apparatus main body. In many cases, the housing integrally supports the cleaning blade and the photosensitive drum. The housing is often formed by resin molding, and there is a problem that a pressing force of the cleaning blade to the photosensitive drum partially changes due to warp of the housing after the molding. Conventionally, a technique is known in which the change of the pressing force caused due to the warp is suppressed by modifying the shape of or a fastening method for a sheet metal member which supports the cleaning blade. In addition, a technique is known in which a manner of attaching a sealing member is modified in order to prevent leak of toner collected by the cleaning blade from deteriorating due to warp of the housing.
In the above conventional techniques, when the housing has warped, it is necessary to adjust the position of the respective cleaning blade in order to uniformize the pressing force of the cleaning blade to the photosensitive drum. In addition, the pressing force changes due to part variation of the cleaning blade, environmental variation, degradation of the cleaning blade caused due to a long period of use, or the like.